Numerous .beta.-adrenergic blocking agents are known for the treatment of various forms of cardiac arrhythmias. It is additionally common to treat some, but not all types of supraventricular tachyarrhythmias, with a .beta.-blocker such as propranolol.
Where .beta.-adrenergic blocking agents are appropriate, substantial oral doses have conventionally been administered chronically in order to control these arrhythmias. A total dose of at least 80 mg per day and up to 1000 mg per day of propranolol, for example, has been recommended to control tachyarrhythmias. A part of this total dosage is usually taken every 4 to 8 hours. The primary objective of such therapy has been prophylactic--i.e. to maintain a reasonable heart rate as opposed to converting the arrhythmia.
Recently, another approach has been followed for treatment of certain tachyarrhythmias. This approach is for acute treatment. It involves a carefully monitored, intravenous titration of a .beta.-adrenergic blocking agent. The need for great care derives from the danger of a .beta.-blockade from injected propranolol. A .beta.-blocking agent which is not significantly diffused in the bloodstream--i.e. a bolus--can drastically lower blood pressure and is capable of causing cardiac standstill on reaching the heart. As a result, this approach has been followed only under direct physician control, normally in a hospital setting.
This relatively new, acute treatment involves the sequential administration of a series of small increments of dilute .beta.-blocker. The administration is performed very slowly; for example, on a metered basis of no more than 1 mg of propranolol per minute. Each separate administration is normally followed by a hiatus of one or two minutes before the next. This technique also utilizes a comparatively minor total dose of .beta.-adrenergic blocking agent, usually less than 10 mg of propranolol. Together, these factors minimize the bolus effect of the drug.
The nasal administration of .beta.-adrenergic blocking agents has also been suggested as a general means for the treatment of cardiac problems. This technique, which involves substitution of nasal for conventional oral or intravenous administration, is described in U.S. Pat. Nos. 4,428,883 and 4,394,390 (the disclosures of which are incorporated hereby by reference). It specifically references treatment of arrhythmias. These patents, however, do not describe any specific procedure or objective.